Accurately controlling the voltage output from a power supply does not simply entail the provision of an input voltage that will, based on the configuration of the power supply, generate the desired output voltage. Providing too high a voltage at too fast a rate will cause the power supply output to overshoot or undershoot the desired voltage. The output voltage overshoot or undershoot may be caused, for example, by a delay in response caused by characteristics of components in the circuitry of the power supply. Devices like inductors and capacitors, as well as other devices having inductive and capacitive qualities, may take time to become charged, and then may discharge to some extent as the power supply approaches steady state. This type of behavior causes the voltage output by the power supply to continually overshoot and then undershoot the desired voltage until equilibrium is achieved.
Voltage overshoot and undershoot may be detrimental to system performance. Voltage overshoot can cause stress to sensitive components in the load (e.g., processors), and at worst may damage sensitive components to the extent where the load may malfunction, resulting in expense and possibly a dangerous situation. Overshoot is also a waste of energy, which may be problematic in portable or mobile devices wherein energy conservation is an important feature. Likewise, undershoot may negatively impact the operation of sensitive components in the load, and activation of the load may be delayed in order to avoid such impact, which may result in reduced system performance. Existing control techniques such as Dynamic Voltage Scaling (DVS) have helped to minimize overshoot and undershoot in power supply output voltage, but are not equipped to handle the demands of emerging applications that are more complicated, more sensitive, and require more accuracy, faster performance, etc. to reduce load stress and conserve energy.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications and variations thereof will be apparent to those skilled in the art.